Multi-degree reconfigurable optical add-drop multiplexing

Abstract

Various architectures of a multi-degree reconfigurable optical add-drop multiplexer with reduced contention are provided. These architectures allow the degree of contention reduction to be managed in a flexible and modular way. The degree of the node and the amount of add/drop at the node can also be managed in a flexible and modular way. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

I claim: 
     
       1. An apparatus, comprising:
 a distributing device configured to accept a first plurality of signals and distribute at least some of the accepted first plurality of signals into a first plurality of groups of signals, each group of the first plurality of groups of signals including zero, one or more than one signal, the distributing device including at least one first coupling element, each of the at least one first coupling element including:
 multiple input ports to accept at least some of the first plurality of signals, and 
 a plurality of output ports to provide at least some of the signals accepted at the input port as one or more groups of signals; 
 
 a combining device configured to accept a second plurality of groups of signals and combine at least some of the accepted second plurality of groups of signals into one or more output groups of signals, each group of the second plurality of groups of signals including zero, one or more than one signal, the combining device including at least one second coupling element, each of the at least one second coupling element including:
 a plurality of input ports to accept at least some of the second plurality of groups of signals with one or more of the input ports coupled to output ports of one or more of the at least one first coupling element, and 
 multiple output ports to provide a respective output group of signals, 
 wherein all the first coupling elements and all the second coupling elements are switchable; 
 
 a signal coupling device coupled to the distributing device and to the combining device, the signal coupling device including:
 a plurality of third coupling elements, each third coupling element configured to accept a respective third plurality of groups of signals of the first plurality of groups of signals from one or more of the least one first coupling element, combine signals of the accepted respective third plurality of groups of signals into a multiplexed drop group of one or more signals, and output the drop group of one or more signals, and 
 a plurality of fourth coupling elements, each fourth coupling element configured to accept at least one add group of one or more signals, distribute signals of the accepted at least one add group of one or more signals into a respective fourth plurality of groups of signals, and provide the respective fourth plurality of groups of signals to one or more of the at least one second coupling element; and 
 
 a reconfiguration device coupled to the signal coupling device, the reconfiguration device including:
 one or more signal removal units, each signal removal unit configured to accept drop groups of one or more signals from two or more of the third coupling elements and to selectively receive one or more signals from the accepted drop groups of one or more signals, at least one of the signal removal unit configured to receive multiple signals assigned to occupy a same portion of wavelength spectrum, at least one of the one or more signal removal units comprising:
 a plurality of splitters or demultiplexers, each of the plurality of splitters or demultiplexers coupled to accept a drop group of one or more signals from a respective one of the third coupling elements through the input port of the respective splitter or demultiplexer and provide a respective plurality of drop groups of one or more signals, 
 a switch coupled to two or more of the plurality of splitters or demultiplexers, and 
 a receiver coupled to the switch, the receiver configured to accept a plurality of drop groups of one or more signals from two or more of the splitters or demultiplexers through the switch and the respective two or more splitters or demultiplexers. 
 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the at least one first coupling element is configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of third coupling elements are configured to selectively combine signals on a single wavelength channel or multiple wavelength channels. 
     
     
       3. The apparatus of  claim 1 , wherein the at least one first coupling element is configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of fourth coupling elements are configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels. 
     
     
       4. The apparatus of  claim 1 , wherein the at least one second coupling element is configured to selectively combine signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of fourth coupling elements are configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels. 
     
     
       5. The apparatus of  claim 1 , wherein the at least one second coupling element is configured to selectively combine signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of third coupling elements are configured to selectively combine signals on a single wavelength channel or multiple wavelength channels. 
     
     
       6. The apparatus of  claim 1 , wherein one or more of the at least one first coupling element is added or removed in service without disrupting existing signal traffic. 
     
     
       7. The apparatus of  claim 1 , wherein one or more of the third coupling elements is added or removed in service without disrupting existing signal traffic. 
     
     
       8. The apparatus of  claim 1 , wherein one or more of the at least one second coupling element is added or removed in service without disrupting existing signal traffic. 
     
     
       9. The apparatus of  claim 1 , wherein one or more of the fourth coupling elements is added or removed in service without disrupting existing signal traffic. 
     
     
       10. The apparatus of  claim 1 , wherein at least one of the one or more signal removal units is added or removed in service without disrupting existing signal traffic. 
     
     
       11. The apparatus of  claim 1 , wherein a number of connections between at least one of the one or more signal removal units and the third coupling elements are increased or decreased in service without disrupting existing signal traffic. 
     
     
       12. The apparatus of  claim 1 , wherein at least one of the signal removal units is configured to receive multiple signals assigned to occupy different portions of wavelength spectrum. 
     
     
       13. The apparatus of  claim 1 , further comprising:
 one or more signal addition units, each signal addition unit configured to selectively distribute one or more signals into one or more add groups of one or more signals and transmit the one or more add groups of one or more signals to two or more of the fourth coupling elements, at least one of the signal addition unit configured to transmit multiple signals assigned to occupy a same portion of wavelength spectrum. 
 
     
     
       14. An apparatus, comprising:
 a distributing device configured to accept a first plurality of signals and distribute at least some of the accepted first plurality of signals into a first plurality of groups of signals, each group of the first plurality of groups of signals including zero, one or more than one signal, the distributing device including at least one first coupling element, each of the at least one first coupling element including:
 multiple input ports to accept at least some of the first plurality of signals, and 
 a plurality of output ports to provide at least some of the signals accepted at the input port as one or more groups of signals; 
 
 a combining device configured to accept a second plurality of groups of signals and combine at least some of the accepted second plurality of groups of signals into one or more output groups of signals, each group of the second plurality of groups of signals including zero, one or more than one signal, the combining device including at least one second coupling element, each of the at least one second coupling element including:
 a plurality of input ports to accept at least some of the second plurality of groups of signals with one or more of the input ports coupled to output ports of one or more of the at least one first coupling element, and 
 multiple output ports to provide a respective output group of signals, 
 wherein all the first coupling elements and all the second coupling elements are switchable; 
 
 a signal coupling device coupled to the distributing device and to the combining device, the signal coupling device including:
 a plurality of third coupling elements, each third coupling element configured to accept a respective third plurality of groups of signals of the first plurality of groups of signals from one or more of the least one first coupling element, combine signals of the accepted respective third plurality of groups of signals into a multiplexed drop group of one or more signals, and output the drop group of one or more signals, and 
 a plurality of fourth coupling elements, each fourth coupling element configured to accept at least one add group of one or more signals, distribute signals of the accepted at least one add group of one or more signals into a respective fourth plurality of groups of signals, and provide the respective fourth plurality of groups of signals to one or more of the at least one second coupling element; and 
 
 a reconfiguration device coupled to the signal coupling device, the reconfiguration device including:
 one or more signal addition units, each signal addition unit configured to selectively distribute one or more signals into one or more add groups of one or more signals and transmit the one or more add groups of one or more signals to two or more of the fourth coupling elements, at least one of the signal addition unit configured to transmit multiple signals assigned to occupy a same portion of wavelength spectrum, at least one of the one or more signal addition units comprising:
 a plurality of combiners or multiplexers, each of the plurality of combiners or multiplexers coupled to accept an add group of one or more signals and provide the add group of one or more signals to at least one of the fourth coupling elements, 
 a switch coupled to two or more of the combiners or multiplexers, and 
 a transmitter coupled to the switch, the transmitter configured to distribute one or more signals into the add group of one or more signals and transmit the add group of one or more signals to two or more of the fourth coupling elements through the switch and the respective two or more combiners or multiplexers. 
 
 
 
     
     
       15. The apparatus of  claim 14 , wherein the at least one first coupling element is configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of third coupling elements are configured to selectively combine signals on a single wavelength channel or multiple wavelength channels. 
     
     
       16. The apparatus of  claim 14 , wherein the at least one first coupling element is configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of fourth coupling elements are configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels. 
     
     
       17. The apparatus of  claim 14 , wherein the at least one second coupling element is configured to selectively combine signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of fourth coupling elements are configured to selectively distribute signals on a single wavelength channel or multiple wavelength channels. 
     
     
       18. The apparatus of  claim 14 , wherein the at least one second coupling element is configured to selectively combine signals on a single wavelength channel or multiple wavelength channels, and wherein the plurality of third coupling elements are configured to selectively combine signals on a single wavelength channel or multiple wavelength channels. 
     
     
       19. The apparatus of  claim 14 , wherein one or more of the at least one first coupling element is added or removed in service without disrupting existing signal traffic. 
     
     
       20. The apparatus of  claim 14 , wherein one or more of the third coupling elements is added or removed in service without disrupting existing signal traffic. 
     
     
       21. The apparatus of  claim 14 , wherein one or more of the at least one second coupling element is added or removed in service without disrupting existing signal traffic. 
     
     
       22. The apparatus of  claim 14 , wherein one or more of the fourth coupling elements is added or removed in service without disrupting existing signal traffic. 
     
     
       23. The apparatus of  claim 14 , wherein at least one of the one or more signal addition units is added or removed in service without disrupting existing signal traffic. 
     
     
       24. The apparatus of  claim 14 , wherein a number of connections between at least one of the one or more signal addition units and the fourth coupling elements are increased or decreased in service without disrupting existing signal traffic. 
     
     
       25. The apparatus of  claim 14 , wherein at least one of the signal addition units is configured to transmit multiple signals assigned to occupy different portions of wavelength spectrum.